Updating your music database?

On average, but after the very first time you do this ever;
how long does it take to update your music database after adding new songs?

(i.e. I have about 50k tracks, and if I upload 2 more albums, (20 tracks more) to my server, it takes Audirvana v3.5 about 30 minutes to update the database.)

If it detects new files bring added, few minutes. Otherwise until the next sync. You can trigger the sync manually.